Estimate your available home equity and a potential HELOC credit line — free, private, no email required.
Lender limits vary. Many lenders cap total borrowing (mortgage + HELOC) at a percentage of your home's value; 80%–85% is a common illustrative range, but your lender's limit may differ.
Assumes no other loans or credit lines are secured by this home. A second mortgage, home equity loan, or existing HELOC reduces the estimate — add those balances (or the full limit of an existing line) to the mortgage field above.
A Home Equity Line of Credit (HELOC) lets you borrow against the equity you've built in your home — the difference between what your home is worth and what you still owe on your mortgage. Instead of receiving a lump sum, a HELOC gives you a revolving credit line, similar in structure to a credit card, that you can draw from as needed up to an approved limit. Lenders typically limit total borrowing (your existing mortgage plus the new HELOC) to a maximum combined loan-to-value ratio, commonly referred to as CLTV, which varies by lender and by your credit profile.
Formula: Maximum HELOC = (Home value × Maximum CLTV%) − Remaining mortgage balance.
For example, on a $450,000 home with an 80% CLTV limit and a $220,000 remaining mortgage: $450,000 × 0.80 = $360,000 maximum combined borrowing, minus the $220,000 mortgage, leaves an estimated $140,000 in potential HELOC credit — before considering your credit profile and the lender's other underwriting criteria. Change any of the three inputs and the estimate updates instantly, entirely in your browser.
Current estimated home value is the foundation of the whole calculation, so it's worth being realistic rather than optimistic. A recent comparable-sales estimate, a recent appraisal, or a conservative online estimate tends to produce a more useful number than a hoped-for future value. Overstating your home's value inflates the estimate and can set expectations a real lender's appraisal won't support.
Remaining mortgage balance is subtracted directly from your maximum combined borrowing, so an outdated balance (for example, one from a year-old statement instead of a current one) can meaningfully skew the result. Use your most recent mortgage statement or online loan-servicer balance for the most accurate estimate.
Combined loan-to-value (CLTV) limit is the lender's cap on how much total debt — your original mortgage plus the new HELOC — can sit against your home's value. This is the input with the most variation across lenders and across borrowers with different credit profiles, so treat the number in this calculator as a starting assumption to test, not a promise from any specific lender. Running the calculator at a couple of different CLTV assumptions (for example, a more conservative one and a more generous one) gives you a realistic range rather than a single number that may not match what you're actually offered.
Say your home is worth $500,000 and you owe $300,000 on your mortgage. Your total equity — what you'd walk away with if you sold the home outright and paid off the mortgage — is $200,000. That is not the same number as what a HELOC lender would let you borrow. If a lender caps combined borrowing at 80% CLTV, the maximum combined debt allowed against the home is $500,000 × 0.80 = $400,000. Subtract your $300,000 mortgage balance, and the estimated maximum HELOC credit line is $100,000 — half of your total equity, not all of it. This gap between "total equity" and "accessible equity" is one of the most common points of confusion for first-time HELOC borrowers, and it's exactly what this calculator is built to make clear.
The single most common mistake is treating a HELOC credit line as free money rather than a loan secured by your home. Every dollar you draw accrues interest and must be repaid; a large available limit is not the same thing as money you've already earned or saved. A second common mistake is ignoring variable-rate risk: most HELOCs carry a variable interest rate, so the payment on a balance you draw today can rise later if the underlying rate index moves, even if you never draw another dollar. A third mistake is borrowing against a home without a repayment plan for when the draw period ends and the loan converts to a repayment period with a different, often higher, monthly payment. None of these risks are unique to any one lender; they are structural features of how a HELOC works, which is why understanding the mechanics before applying matters more than shopping for the lowest advertised rate alone.